Bio-threat detectors are used to monitor the ambient air to detect the presence of potentially harmful pathogens. In general, air is drawn into a collection and detection apparatus where the particulates in the air are evaluated. Airflow into the collection and detection apparatus is typically generated by a fan within the apparatus. The apparatus continuously monitors the air and the individual molecules within a given airflow. Some detectors use lasers or LEDs to scan the air path to interrogate the particles passing through. A harmless particle, such as a dust particle, can be discriminated from a harmful particle, for example an anthrax spore, because each different type of particle reflects a different wavelength of light. Light reflected off the passing particles is matched to a database of known wavelengths, a match indicating a biological entity is present. When a matching wavelength is detected, a triggering mechanism within the detection apparatus is activated. When the triggering mechanism is activated, a trigger signal is generated which indicates that a potential pathogen is present. However, the specific type of particle is not identified by such a collection and detection apparatus.
A confirmation process is initiated once the triggering mechanism signals the presence of a possible pathogen. During the confirmation process, the particles that triggered the detection apparatus are identified. Conventionally, when the trigger signal is generated, the potential pathogen is collected and taken to a lab where an analysis is performed. Multiple techniques are performed to identify the potential pathogen, each technique is designed to identify a different type of pathogen, typically performed under the supervision of a lab operator. This is a time-consuming process requiring various pieces of test equipment, which is impractical for real-time threat assessment. Such processes also require the interaction of a human operator, which is costly and often inefficient. Continuous monitoring and processing of potential pathogens, over a 24 hour a day period, requires multiple such human operators to cover the desired time frame.
A step in the identification process includes capturing and purifying potential pathogens from within a fluid sample. For large volume fluid samples, such as 1 ml or greater, extraction of the potential pathogens is problematic due to the relatively lengthy time frame required. In one method, the fluid sample is exposed to a binding surface area, yet for a large volume, the amount of time for the pathogens within the fluid sample to diffuse to the binding surface is unacceptably long, or the flow rate past the binding surfaces is too slow in some applications. In another method, the fluid sample is cultured to enable the pathogen to grow, if present. However, the time period for culturing is also unacceptably long in some applications.